Right season , wrong season, even in the good season serious stuff happen, take the med in summer, Mistrals, Levantes, meltemis, a strong levante can blow a solid 40 or 50, a mistral even 60 knts, the trip from Poli to NZ is tough, every year in the way back to Eu from the caribbean someone found a nasty front or low , in Argentina you got the pampero, and even when the weather FX is okey, things turn wrong, there is not such good season or bad season, there is Hurricane, ciclone, typhon season, monzonic season....In summer you can get a nasty gale in Biscay,
now somepeople sail following the pilot charts and the wind roses looking for the 4 or 5 numbers in the center , nothing is granted

For sure, yes. At least a storm jib, 100%. Here's a typical experience of mine with storm sails, tri and staysail. Panama, Colon side, getting ready to blast north for the YucatanPassage in December. Blowing like stink at our final anchorage getting ready for sea. Outside the massive breakwaters are ships galore, and it's blowing 25 and gusting higher. Since it's easier to leave with the storm sails set than to reef down in big waves with ships all over, let's just be conservative and leave with the storm tri and storm staysail up.

Long story short, we never put a stitch more sail up for the next ten days, it just blows and blows, and by the time we're around Cuba our storm tri and jib are beat/flogged/rubbed/worn to hell. Our regular staysail has a row of reef points, and I use them, as did the old main, naturally. But if I had left Panama just using reefed main and staysail (and a rolled up Yankee that was never unrolled a minute) both of these primary sails probably would have been ruined. Instead, some heavy duty sails just got taken to a sail maker for reinforcing where they were worn, lost hanks etc. My old main and current staysail rested down below during that high-wind Caribbean crossing, and were in good shape when we saw less than 20 knots wind after about two weeks.

If nothing else, dedicated storm sails can save a lot of life on your primaries.

This pretty well sums things up. Partly depends on your size too. We are 58 feet, ketch, roller in mast for both main & mizzen, 135 #1, 105% 3/4 hoist heavy staysail, storm trisail on its own track. I would hate to damage the #1 and I prefer to not operate a jib partly rolled. In the event we are headed off to face really bad pizza or the #1 is wrecked, we have an old super heavy dacron chicken genoa with 3/4 hoist. The trisail saves the roller furl main by the same logic. One additional strong point for the trisail - the boom is no longer a flogging missile so the danger level is reduced as well as the likelihood of damage to the boom or goose neck. Our boom is several hundred pounds so this is better for us. Put your trisail on the track in a bag and tie it down. In a pinch, you will only have to attach the halyard & sheets. CAUTION: In our case, the trisail halyard can accidentally get wound into the main as the main is furled - DISASTER! Totally furl the main before retrieving the trisail halyard from its safe spot.

BTW - I highly recommend The Pardy's little book "Storm Tactics" This runs down many options and how you might expect it to work for you based on a variety of boat types. I re-read this from time to time. I picked it up at one of their lectures at the All Sail Chicago show. The talk was great too.